The S-51 was an early postwar development of the R-5. Although intended for the civilian market, most S-51s went into military service. They served with all the US military services as well as with the air forces of Australia, Britain, Canada and France. The seven RCAF S-51s were designated H-5. The first helicopters in the RCAF, they were used mainly for training and experimentation, although some did search-and-rescue work. All H-5s were retired by the mid-1960s. The United States built 214, and 165 were made in Britain.
For rescue operations the H-5 could be fitted with external closed stretcher carriers. The US Air Force used S-51s extensively for casualty evacuation and the recovery of downed pilots during the Korean war.
The Museum example was the first helicopter built for the RCAF in 1947 and served until 1959. It was then stored until transferred to the Museum in 1964.